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authorTrond Myklebust <Trond.Myklebust@netapp.com>2012-09-27 15:44:19 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2012-09-28 13:42:41 -0400
commite9ab41b620e4b679ed069ab05cb85e67870b7c87 (patch)
tree4b61840469aadfc05296e8b6859b6640e9d43193 /fs/nfs/idmap.c
parentNFSv4: Remove BUG_ON() and ACCESS_ONCE() calls in the idmapper (diff)
downloadlinux-dev-e9ab41b620e4b679ed069ab05cb85e67870b7c87.tar.xz
linux-dev-e9ab41b620e4b679ed069ab05cb85e67870b7c87.zip
NFSv4: Clean up the legacy idmapper upcall
Replace the BUG_ON(idmap->idmap_key_cons != NULL) with a WARN_ON_ONCE(). Then get rid of the ACCESS_ONCE(idmap->idmap_key_cons). Then add helper functions for starting, finishing and aborting the legacy upcall. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Bryan Schumaker <bjschuma@netapp.com>
Diffstat (limited to 'fs/nfs/idmap.c')
-rw-r--r--fs/nfs/idmap.c65
1 files changed, 44 insertions, 21 deletions
diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 79f6424aa081..8222ad861456 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -330,7 +330,6 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
name, namelen, type, data,
data_size, idmap);
- idmap->idmap_key_cons = NULL;
mutex_unlock(&idmap->idmap_mutex);
}
return ret;
@@ -662,6 +661,34 @@ out:
return ret;
}
+static bool
+nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
+ struct key_construction *cons)
+{
+ if (idmap->idmap_key_cons != NULL) {
+ WARN_ON_ONCE(1);
+ return false;
+ }
+ idmap->idmap_key_cons = cons;
+ return true;
+}
+
+static void
+nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
+{
+ struct key_construction *cons = idmap->idmap_key_cons;
+
+ idmap->idmap_key_cons = NULL;
+ complete_request_key(cons, ret);
+}
+
+static void
+nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
+{
+ if (idmap->idmap_key_cons != NULL)
+ nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
+}
+
static int nfs_idmap_legacy_upcall(struct key_construction *cons,
const char *op,
void *aux)
@@ -686,21 +713,17 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons,
if (ret < 0)
goto out2;
- if (idmap->idmap_key_cons != NULL) {
- WARN_ON_ONCE(1);
- ret = -EAGAIN;
+ ret = -EAGAIN;
+ if (!nfs_idmap_prepare_pipe_upcall(idmap, cons))
goto out2;
- }
- idmap->idmap_key_cons = cons;
ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
- if (ret < 0)
- goto out3;
+ if (ret < 0) {
+ nfs_idmap_abort_pipe_upcall(idmap, ret);
+ kfree(data);
+ }
return ret;
-
-out3:
- idmap->idmap_key_cons = NULL;
out2:
kfree(data);
out1:
@@ -741,14 +764,15 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
struct key_construction *cons;
struct idmap_msg im;
size_t namelen_in;
- int ret;
+ int ret = -ENOKEY;
/* If instantiation is successful, anyone waiting for key construction
* will have been woken up and someone else may now have used
* idmap_key_cons - so after this point we may no longer touch it.
*/
cons = idmap->idmap_key_cons;
- idmap->idmap_key_cons = NULL;
+ if (cons == NULL)
+ goto out_noupcall;
if (mlen != sizeof(im)) {
ret = -ENOSPC;
@@ -778,7 +802,8 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
}
out:
- complete_request_key(cons, ret);
+ nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
+out_noupcall:
return ret;
}
@@ -789,12 +814,9 @@ idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
struct idmap_legacy_upcalldata,
pipe_msg);
struct idmap *idmap = data->idmap;
- struct key_construction *cons;
- if (msg->errno) {
- cons = idmap->idmap_key_cons;
- idmap->idmap_key_cons = NULL;
- complete_request_key(cons, msg->errno);
- }
+
+ if (msg->errno)
+ nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
/* Free memory allocated in nfs_idmap_legacy_upcall() */
kfree(data);
}
@@ -804,7 +826,8 @@ idmap_release_pipe(struct inode *inode)
{
struct rpc_inode *rpci = RPC_I(inode);
struct idmap *idmap = (struct idmap *)rpci->private;
- idmap->idmap_key_cons = NULL;
+
+ nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
}
int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)